I wouldn't call that size a small power bank. That chip is in the same ballpark as gaming GPUs, and based on the VRMs in the picture it probably draws about as much power.

But as you said, the next generations are very likely to shrink (especially with them saying they want to do top of the line models in 2 generations), and with architecture improvements it could probably get much smaller.

I’m old enough to remember your typical computer filling warehouse-sized buildings.

Nowadays, your average cellphone has more computing power than those behemoths.

I have a micro SD card with 256GB capacity, and I think they are up to 2TB. On a device the size of a fingernail.